An organic electroluminescence (EL) device using an organic substance is a promising solid-state emitting type inexpensive and large full-color display device, and has been extensively developed. In general, an organic EL device includes an emitting layer and a pair of opposing electrodes holding the emitting layer therebetween. When an electric field is applied between the electrodes, electrons are injected from the cathode and holes are injected from the anode. Emission is a phenomenon in which the electrons recombine with the holes in the emitting layer to produce an excited state, and energy is emitted as light when the excited state returns to the ground state.
The performance of an organic EL device has been gradually improved with improvements in emitting materials for an organic EL device. In particular, improvement in color purity (shortening of emission wavelength) of a blue-emitting organic EL device is an important factor leading to high color reproducibility of a display.
As examples of a material for an emitting layer, Patent Documents 1 to 8 disclose diaminopyrene derivatives. Patent Documents 3 to 8 disclose organic EL devices using a diaminopyrene derivative as a doping material. Indeed, by using the materials described in these documents, properties of the organic EL device can be improved. However, it is difficult to obtain pure blue light emission, whereby it is not easy to use those materials as a material for a display. Patent Documents 1 and 2 disclose diaminopyrene derivatives which can emit blue light having a short wave length. However, there is a problem that the luminous lifetime of the organic EL devices obtained by using these materials is very short.    Patent Document 1: Korean Patent Publication No. 10-2007-0115588    Patent Document 2: Korean Patent Publication No. 10-2008-0079956    Patent Document 3: WO2005/108348    Patent Document 4: WO2004/018588    Patent Document 5: WO2004/018587    Patent Document 6: WO2009/102054    Patent Document 7: WO2009/102026    Patent Document 8: WO2009/107596